Bale, an apparatus and a method for the wrapping of a bale in two crossing wrapping layers applied in overlapping helical turns

ABSTRACT

A method for packaging bales (1) with strips of plastic packaging film (9), in which a bale is rotated about a generally horizontal axis (3) and, when appropriate, about a generally vertical axis (6), and wherein film is taken from a film magazine (7) spaced from the bale and wrapped around the bale in successive turns while maintaining the film under tension, and wherein the film in each turn of film around the bale extends generally parallel with and transversely to the horizontal axis. The method is mainly characterized in the bale (1) is then wrapped with a further wrapping of film (9), and in that successive turns (9&#34;) of this further wrapping cross-over those parts of the turns (9&#39;&#34;) of the underlying film which extend generally parallel with the horizontal axis (3), in a manner to retain the underlying turns. This film material is held under tension while being applied. The invention also relates to an arrangement for carrying out the method, and to a bale.

BACKGROUND OF THE INVENTION

The present invention relates to a method for wrapping or packagingbales in strips of plastic packaging film, in which the bale is rotatedabout a generally horizontal axis and, when appropriate, also about agenerally vertical axis, and in which packaging film is taken from afilm magazine located at a distance from the bale and wrapped insuccessive turns around the entire bale while maintaining a tensionforce in the film, and in which the film in each turn extendsessentially parallel with and transversely to the horizontal axis.

The invention also relates to an arrangement for carrying out themethod, and to bales.

Methods and arrangements of the aforesaid kind are known essentially.One large area of use is found in the wrapping of bales of animalfodder, ensilage, which is still not dry and which is to be wrapped inan air-impervious plastic film wrapping. Present-day bales have anessentially circular cross-section, i.e. they are not parallelepipedic.

The known technique, however, is encumbered with serious drawbacks. Inorder for ensilage to be wrapped in the manner intended, it is necessaryfor the wrapped bale to be truly airtight. Even though the film wrapperis maintained under considerable tension as it is wound, it is extremelydifficult to achieve the requisite tension in the wrapper and requisiteretention of the wrapping material around the bale, particularly onthose parts of respective turns which are parallel with horizontal axis.At times, the joints produced with the aid of glue applied to the sideof the film which faces towards the bale are insufficiently strong,therewith allowing moisture and air to enter the bale material. Thisingress of air and moisture will destroy the bale material, due to mouldgrowth among other things. Toxic substances are also likely to form.When moisture is present, the adhesive force exerted by the glue willdiminish progressively, thereby quickly worsening the situation. Theproblem is, of course, still greater in the absence of glue joints. Onecontributory factor to the described moisture susceptibility withinsufficient retention of the wrapping turns is that the joints on oneof the turn-parts parallel with the horizontal axis of each turn opensupwardly and is therefore susceptible to rain, etc. On the other ofthese two parts of the turn, however, the joints are downwardly open,i.e. a certain "roof tile effect" is obtained.

When practicing the known technique, it cannot be guaranteed that auniform and high bale material quality will be achieved.

The problems of poor wrapper tension and poor wrapper retention increasewhen passing from cylindrical bales to generally parallelepipedic bales,this transition being desirable for storage and transportation reasons,among other things. This worsening of the problem is mainly because thesides of a parallelepipedic bale are mutually parallel and because whenwrapped, the bale has a certain dog-leg configuration, which furtherimpairs the situation.

SUMMARY OF THE INVENTION

The present invention relates to a method and to an arrangement by meansof which the aforesaid problems are solved. Thus, the invention providesan impervious and moisture-insensitive bale.

Thus, the invention relates to a method for wrapping or packaging balesin bands of plastic packaging film, wherein a bale is rotated about agenerally horizontal axis and, when appropriate, also about a generallyvertical axis, wherein film is taken from a film magazine spaced fromthe bale and wrapped around the entire bale in successive turns whilemaintaining the film band under tension, and wherein the film in eachwrapping turn around the bale extends generally parallel with andtransversely to said horizontal axis.

The method is mainly characterized in that further bale wrapping film isapplied to the bale while maintaining an elastic tension force orstretch in said film, wherein successive turns of this further balewrapping film cross over those parts of the film-turns of the underlyingfilm which extend generally parallel with said horizontal axis such asto retain said film turns.

The invention also relates to an arrangement for wrapping bales instrips of plastic packaging film, comprising means for rotating a baleabout a generally horizontal axis and, when appropriate, about agenerally vertical axis, a film magazine spaced from said bale, meansfor removing film from said film magazine while maintaining the filmunder tension, and means for wrapping the film band in successive turnsaround the bale, wherein according to a first wrapping method the filmis wrapped around the entire bale with the film in each wrapping turnextending generally parallel with and generally transversely to thehorizontal axis of the bale, and wherein in accordance with a secondwrapping method film is wrapped around the outer bale surface with thefilm in each wrapping turn extending generally transversely to thedirection of the horizontal axis of the bale.

The arrangement is mainly characterized in that wrapping of a bale isintended to be effected first in accordance with said first wrappingmethod and then in accordance with said second wrapping method, suchthat further film, in accordance with said second wrapping method, isapplied to the bale in successive wrapping turns, wherein said furtherwrapping turns cross-over in an elastically tensioned and retainingstate the underlying parts of the wrapping turns which extend generallyparallel with said horizontal axis; wherein in those instances when thebale is supported for rotation about a generally vertical axis by meansof a supporting device, the supporting device is intended to achievethrough oscillatory, alternating, limited rotation reciprocating windingof turns of said further film with a given turn pitch, and in thosecases when the film magazine is mounted for pivotal movement about agenerally vertical axis, and therewith around the bale, the filmmagazine is intended to produce reciprocal winding of turns of saidfurther film at a given turn pitch through oscillatory, alternating,limited swinging movement of the film magazine.

The invention also relates to a bale, primarily an ensilage bale,wrapped in band-like packaging film, wherein the entire bale is wrappedin a first wrapping comprising successive turns of film applied whilemaintaining tension in said film and rotating the bale about asubstantially horizontal axis and extending parallel with andtransversely to said horizontal axis.

The bale is mainly characterized in that the wrapping includes a secondwinding of additional film which is applied subsequent to applying thefirst winding while maintaining the film under tension, such thatsuccessive turns of said further film will cross-over those parts of theturns of the first winding which extend generally parallel with saidhorizontal axis in an elastically stretched state such as to retain orhold firm the turns of said first winding.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in more detail with reference toexemplifying embodiments thereof and also with reference to theaccompanying drawings, in which

FIG. 1 is a perspective view of a first embodiment of an inventivearrangement;

FIG. 2 is a side elevational view of the FIG. 1

FIG. 3 is a schematic illustration of the arrangement shown in FIGS. 1and 2, seen in the same direction as FIG. 2, and shows the applicationof film in accordance with the invention;

FIG. 4 is a schematic illustration of the FIG. 3 arrangement, as seenfrom above in FIG. 3;

FIGS. 5a-5c illustrate schematically an arrangement for securing plasticfilm to a bale and winding the film in a crossing direction in a secondwinding or wrapping station, the arrangement being shown from the samedirection as in FIG. 3;

FIG. 6 illustrates schematically an arrangement for winding or wrappingplastic film in a crossing direction firmly to a bale in a secondwinding or wrapping station; and

FIG. 7 is a diagram which illustrates the hydraulics of an inventiveapparatus functioning to wrap or wind a plastic strip crosswise around abale, both parallel with and transversely to the horizontal axis of thebale.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 illustrates an exemplifying embodiment of an arrangement forpackaging bales 1. The arrangement includes an endless conveyor belt 2which is intended to rotate the bale about a generally horizontal axis3. In the illustrated case, there is formed in the belt 2 a hollow 4which extends generally in the direction of the horizontal axis 3 and inwhich a bale 1 is intended to be rotated. The conveyor belt is supportedby a support structure 5, a table structure, which can be rotatedseparately about a generally vertical axis 6, thereby enabling the bale1 to be rotated or turned about a generally horizontal axis 3 and agenerally vertical axis 6.

Spaced from the bale 1 is a film magazine 7, which in the illustratedcase has the form of a film roll 8 from which film 9 is intended to runto the bale while maintaining tension force in the film. Although notshown, means are provided for applying a braking force in the vicinityof or to the film magazine in order to obtain and maintain the tensionforce.

According to a first winding or wrapping method, the film is wrappedaround the entire bale 1 in successive, preferably overlapping turns,such that the film in each turn 9' around the bale will extend generallyparallel with and transversely to the horizontal axis 3, as shown inFIGS. 1 and 2. In this case, the bale is rotated around the horizontalaxis 3 and the vertical axis 6. According to one alternative, not shown,the film magazine 7 is arranged for rotation around the bale, in whichcase it is the film magazine which is rotated, or swung, around apreferably generally vertical center axis, the rotational axis of themagazine, and not the bale.

When the entire bale has been packaged by this first wrapping or windingmethod, additional film 9 is wrapped around the bale 1 in accordancewith a second wrapping or winding method, FIGS. 3 and 4, this furtherfilm being applied in successive preferably mutually at least partlyoverlapping turns 9" in a manner to cross-over those parts 9"' of theunderlying film turns 9' that extend generally parallel with thehorizontal axis 3 in a manner to firmly hold the underlying wrappingthrough the action of the elastic holding force in the tensioned filmwrapping band. This further film is applied while rotating the bale 1solely about said horizontal axis.

In order to obtain a given pitch in the film turns 9" of said further

film material, the bale 1 is at least limitedly rotatable about agenerally vertical axis, this rotation of the bale achieved in the caseof the illustrated embodiment by means of the table 5. The film wrappingmaterial is wound backwards and forwards by alternating, oscillating,limited rotation of the table. The partial oscillation of the table 5,while the supply roll is axially stationary, allows the winding of thewrapper along the length of the bale to create overlapping turns 9".

In the case of an embodiment in which the film magazine 7 can be swungaround the bale 1 the pitch of the further film turns 9" is achieved byarranging the film magazine for at least limited rotation and also forat least limited movement in the direction of said horizontal axis,wherein reciprocating winding of the film material around the bale isachieved by limited alternating, oscillating, rotary movement of thefilm magazine around said rotational axis.

According to one preferred embodiment, the film magazine thus includes arotatable roll of film which, when applying film in accordance with thefirst wrapping method, is intended to take a first position in which theroll axis extends generally vertical and which, when applying furtherfilm in accordance with the second wrapping method, is intended to takea second position in which the roll axis is generally horizontal,wherein the roll can preferably be lowered and raised between thesepositions. In the illustrated embodiment, the roll axle is pivotallymounted on a pivot means 10 and a preferably hydraulic piston-cylinderdevice 11. In this particular case, both the first wrapping method andthe second wrapping method are intended to be carried out in one and thesame wrapping arrangement, i.e. in one and the same wrapping or windingstation.

Arrangements which have a higher total production capacity are alsoconceivable, where the first wrapping method is carried out in a firstwrapping station and the second wrapping method is carried out in asecond wrapping station, wherein wrapping or winding in crosswisefashion of the wrapping of the entire bale achieved in the first stationis carried out in the second station. In this case, with regard to saidfirst station, the arrangement can either be of the kind in which a bale1 is supported on the table 5, FIG. 1, which can be rotated about agenerally vertical axis 6, or of the kind in which the film magazine isrotatable about a bale, as mentioned briefly above.

Thus, when wrapping of the bale in accordance with the first wrappingmethod in the first station is completed, the bale 1 is transferred bysuitable means and in a suitable manner to a second wrapping or windingstation where the bale is wrapped in accordance with the second wrappingmethod, subsequent to severing the film extending from the bale to thefilm magazine in the first station, and thereby breaking the connectionof the bale with said first station.

Similar to the first station, the second station may either be of thekind which includes a rotatable table 5, or of the kind which includes arotatable, swingable, film magazine?.

Various methods and arrangements are conceivable for securing filmmaterial in the second station to the bale wrapped in the first station.According to a first embodiment, FIGS. 5a-c, in which the arrangement inthe second station includes a rotatable table 5, appropriate filmholding and film separating devices 12 are provided adjacent the table 5and function, for instance, to sever a wrapped bale from the filmmagazine by clipping or likewise cutting the film, and then to hold thefilm end 13 connected to the film magazine 7, as indicated in FIG. 5a,where the holding and separating device is intended to be brought into afilm web separating position, for instance by means of a pivotal arm 14or the like. In the case of the embodiment illustrated in FIGS. 5a-c,the film is intended to be fastened to the bale located on the table byinitially rotating the table 5 about the axis 6, for example through onerevolution, whereupon the film is taken from the magazine 8 and wrappedaround the bale, FIG. 5b, therewith forming at least a part of a fixedturn 15, preferably a complete fixed turn, around the bale. It is alsoconceivable to apply more than one fixed turn 15. Winding of the film ina cross-over fashion is then commenced, by rotating the bale about itshorizontal axis, said bale preferably being rotated in ancounter-clockwise direction in FIG. 5c, so as to draw the film inbeneath the bale. When bale rotation has begun, the holding andseparating device is intended to release the end 13 of the film. Asearlier described, the film is wound around the bale during limitedoscillatory rotation of the table, so that the film will be distributedacross the outer surface of the bale. Upon completion of this balewrapping process, the bale is separated from the magazine and the end ofthe film attached to the magazine is held by the holding device.According to one variant, both a rotatable table and a holding andseparating device are used, and the table together with the device isintended to rotate to a limited extent, such as through one-half of arevolution, from a position corresponding to the position in FIG. 5a, inwhich film is withdrawn from the magazine and laid over the table, FIG.6, prior to placing a bale on the table 5. As illustrated schematicallyin FIG. 6, a bale is placed on the film thus laid over the table,therewith clamping the film firmly between the bale and the table. Anyadhesive on the film will assist in holding the film firmly on the balewrapped in the first station. Rotation of the bale around its horizontalaxis is then commenced, preferably counter-clockwise in an arrangementcorresponding to the FIG. 5a arrangement, wherein the film is drawn inbeneath the bale and the end of the film is released from the holdingdevice 12. This results in firmer attachment of the film to the bale andwrapping of the bale in accordance with the second wrapping method canbe completed in the earlier described manner and the bale separated fromthe magazine. According to one preferred embodiment, also applicable inthe two last described embodiments, the film magazine is swingable abouta generally vertical axis so as to adapt to the different positions ofthe film along the outer surface of the bale, the axial extension of thefilm magazine being generally horizontal when applying the cross-overwinding or wrapping.

Attachment of the film to the bale in the second station can be effectedessentially in a corresponding manner in those instances when thearrangement is of the kind which includes a film magazine that can beswung around the bale. This arrangement will also include a holding andseparating device 12 separate from the film magazine. According to afirst embodiment, the film is attached to the bale by swinging themagazine, for instance, in a manner to obtain one fixed turn around thebale. The bale is then rotated about its horizontal axis so as to windthe film material in a cross-over fashion according to the secondwinding method, while swinging the film magazine, said bale preferablybeing rotated so that film is drawn in beneath the bale. The film ispreferably released from the holding device 12 as said rotation iscommenced. According to another embodiment, the holding and separatingdevice includes a pivotal arm or like member (not shown) which functionsto move the film-end connected to the magazine from a film separatingposition and across the table, therewith drawing film from the magazineand placing the film over the table. A bale is then placed on the table,clamping the film firmly between the bale and the table and fasteningsaid film to the bale. Cross-over winding of the film around the bale iseffected by rotating the bale about its horizontal axis, preferably sothat film will be drawn in beneath the bale. The film is released fromsaid device as the bale begins to rotate about its horizontal axis. Itis also preferred in the two latest described embodiments in which theaxis of the film magazine is generally horizontal that the magazine canbe swung around a generally horizontal axis so as to adapt to thedifferent positions of the film along the outer surface of the bale.

In the hydraulic circuit illustrated in FIG. 7 for an arrangement inwhich both said first winding or wrapping method and said second windingor wrapping method are effected in one and the same station, thereference sign X identifies a system for rotating a bale-carrying tableabout a vertical axis or for swinging a film magazine around a baleplaced on the table. Also shown in FIG. 7 is a hydraulic motor 16, asystem Y which functions to move the film magazine between two positionscorresponding to wrapping of a bale in accordance with the firstwrapping method and wrapping of the bale in accordance with the secondwrapping method, a hydraulic piston 11 by means of which movement of thefilm magazine is achieved, a system Z for rotating a bale about itshorizontal axis, and hydraulic motors 17 which function to drive tablerollers. Reference sign V₁ identifies a first valve and reference signV₂ identifies a second valve, which are preferably of the so-calledclosed center-type and have two inlets and two outlets and areelectromagnetically adjustable. The FIG. 7 system also includes anelectromagnetically adjustable check valve 18, adjustable constant flowvalves 19, 20, 21, 22 and a swivel 23 which functions to transferhydraulic medium in a rotating element, in this case the axle 6, or apivot axle broken-line swivel 23 about which the film magazine isswingably arranged. The reference P identifies a hydraulic pump to whichpipes are connected, while reference T identifies a hydraulic mediumtank and connected pipes.

Wrapping of a bale in accordance with the first wrapping method isintended to be effected with function b activated by the valve V₁, i.e.the P-A and T-B connection, with the check valve 18 open, i.e. theright-hand function 18' activated and not the back function 18". Thevalve V₂ adopts a closed center position. In this case, the tablerotates or the film magazine is swung at a constant speed in apredetermined direction, the hydraulic piston moves the film magazine toa position corresponding to the first wrapping method and the hydraulicmotors 17 which function to rotate a bale about its horizontal axis aresupplied with working medium through the constant flow valve 19, so asto achieve a satisfactory high bale rotation speed with respect to therotational/pivotal speed of the table/magazine. Hydraulic medium exitingfrom the hydraulic motor 16 for the table/magazine returns to the tankvia the check valve 18. At the transition to the second wrapping method,the function a of the valve V₁, i.e. the P-B or T-A connection, isactivated and the function a and the function b of the valve V₂ isactivated alternately. The check valve adopts its blocking position.This causes the table/magazine to rotate/swing slowly through a limitedextent, the hydraulic piston to move the magazine through a positioncorresponding to the second wrapping method, and the hydraulic motors torotate the bale about its horizontal axis relatively quickly, via theconstant flow valve 20.

The illustrated hydraulic circuit arrangement enables a bale wrappingoperation to be controlled very effectively with the aid of relativelyfew components. The use of a check valve to empty the hydraulic pump inX saves the use of a valve of the V₁ and V₂ type. Although not shown,the arrangement includes a control unit for controlling the valves in amanner to obtain the desired bale wrapping cycles. In view of, amongother things, the considerably accuracy of the constant flow valvesused, this control can be based on time measurement for instance, i.e.by activating the two bale wrapping methods during predetermined timeperiods controlled by the control unit.

The inventive method and the manner of operation of the inventivearrangement will be understood in all essentials from the aforegoing.Thus, subsequent to wrapping a bale with film in accordance with thefirst bale wrapping method, additional film is wrapped around the balein accordance with the second bale wrapping method. The bale, which isnormally compacted or compressed to some extent in the direction of itshorizontal axis by the force exerted by the first elastically tensionedwrapping film, will be compressed radially in a direction transverselyto the horizontal axis by the force exerted by the additional film. Inthis case, the underlying film turns are held and tensioned so as toobtain an extremely tightly wrapped, impervious and durable balepackage. The mutually retaining cross-over turns of said further plasticfilm also generate an elastic holding force around the outer surface ofa circular bale or transversely to the long sides of a parallelepipedicbale. This cross-over force is not found with the earlier known balewrapping methods. The joints between adjacent plastic-film turns is aweak point in packaging of the kind meant here, and by applying aretaining, elastically tensioned plastic-film band around a bale in across-over fashion, the weakness of the joints in the plastic film firstapplied is eliminated and the package will remain tight and imperviousfor a long period of time.

It will be understood from the aforegoing that the invention providesparticularly large benefits in comparison with previously known methods.The risk of the inventive packaging being pervious and allowing theingress of moisture, etc. is practically non-existent. Furthermore, theuse of plastic film is very effective insomuch that the number of turnswhen wrapping in accordance with the first wrapping method can bereduced considerably compared to the number of turns needed whenapplying the known technique, since additional film is applied in aretaining and cross-over fashion in accordance with the second balewrapping method. This will result in a reduction in the amount of filmmaterial used, in many cases.

The invention has been described in the aforegoing with reference todifferent embodiments thereof.

It will be understood, however, that other embodiments and minormodifications are conceivable without departing from the inventiveconcept.

For example, other devices, such as drive rollers which act on a balefrom beneath and/or from above are conceivable for effecting rotation ofthe bale around said horizontal axis.

Furthermore, the invention is not restricted to the use of round bales,but can be applied very effectively with bales of generallyparallelepipedic configuration.

Neither is the invention restricted to ensilage bales, but can be usedto wrap bales of varying materials, such as straw, hay, etc.

The term packaging film as used here has a wide interpretation and isintended to cover plastic bands or plastic webs within a wide thicknessrange.

According to one embodiment which is preferred in some instances, thebale wrapping produced in accordance with said first and said secondbale wrapping methods is supplemented with a wrapping of essentially thesame kind as that produced by the first wrapping method, subsequent toapplying a wrapping in accordance with said second wrapping method. Thissupplementary wrapping is appropriate in those instances when thecross-over wrapping produced in accordance with the second wrappingmethod extends out over the ends of the bale. The supplementary wrappingeliminates the risk of pockets forming in the film at the ends of thebale.

The film may also be secured in the second wrapping station in mannersdifferent to those described, for instance by pressing the end of thefilm into the bale.

The pitch of the further, cross-over wrapping produced in accordancewith the second wrapping method can be achieved by causing the filmmagazine to move reciprocatingly along the bale, for instance in guidesor the like, essentially parallel with the horizontal axis.

Embodiments are also conceivable in which the further, cross-overwrapping 9" is applied by rotating, swinging, the film magazine about anaxis parallel with the bale axis, said bale being preferably supportedwith its axis generally vertical, so as to leave the outer surface ofthe bale free. Embodiments of a similar kind are conceivable in whichthe bale is rotated about its axis and the magazine is not moved aroundthe bale. In both instances, the bale will be supported through theintermediary of one or both end parts of the bale.

The invention is thus not restricted to the aforedescribed andillustrated embodiments, since modifications can be made within thescope of the following claims.

I claim:
 1. An arrangement for packaging bales of organic material, suchas animal-feed for ensiling, straw or hay, with strips of plasticpackaging film, comprising means for rotating the bale about a generallyhorizontal axis, means for rotating the bale about a generally verticalaxis, a film magazine including a film roll rotating about an axis fromwhich film is taken while maintaining the film under tension, a balesupporting device (5) which is adapted to carry and support the bale forrotation about said generally vertical axis, said device (5) beingoperable to move in an oscillatory, alternating, limited rotational pathand, means for moving said film roll between a first position whereinthe roll is generally vertical and a second position wherein the roll isgenerally horizontal.
 2. An arrangement according to claim 1, whereinthe moving means comprises a pivot means to which an axle of the filmroll is connected, and means for rotating said film roll about saidpivot means.
 3. An arrangement according to claim 2, wherein said meansfor rotating said film roll includes a hydraulic piston-cylinder device.4. An arrangement according to claim 1, 2 or 3, wherein the filmmagazine (7) from which film is taken can be swung about a generallyvertical axis for adaptation of different positions of the film along anouter surface of the bale.
 5. An arrangement according to claim 1,wherein said means for rotating the bale about said horizontal axisincludes an endless belt conveyor (2) which is adapted to rotate thebale (1) about said horizontal axis (3), said conveyor having a hollow(4) which extends in the direction of said horizontal axis and in whichthe bale is arranged for rotation.
 6. An arrangement according to claim1, wherein the bale-supporting device can be rotated independently ofthe means for rotating the bale about a generally horizontal axis.
 7. Anarrangement according to claim 1, wherein the film magazine is in agenerally fixed location relative to the supporting device.
 8. Anarrangement for packaging bales of organic material, such as animal-feedfor ensiling, straw or hay, with strips of plastic packaging film,comprising means for rotating the bale about a generally horizontalaxis, a film magazine including a film roll from which film is takenwhile maintaining the film under tension, a bale supporting device whichis adapted to carry and support the bale, means for moving said filmroll between a first, generally vertical position and a second,generally horizontal position, means for moving said film roll aroundthe bale about a generally vertical axis while said film roll is in saidgenerally vertical position, and means for pivoting said film roll in anoscillating, alternating manner as said film roll is moved around thebale.